Zhang Sanfeng was a Taoist priest of the Yuan and Ming dynasties. His given name is Tong, also known as Quanyi, with the courtesy name Junshi and the pseudonym Xuanxuanzi. Because he is usually unkempt, he is called "Zhang Scruffy". From Yizhou, Liaodong (now southwest of Zhangwu, Liaoning Province). It is also said to be a descendant of the Celestial Master Zhang. Legend has it that he was tall and imposing, with big ears, round eyes, a turtle-shaped back like a crane, and a beard and beard like a halberd. Throughout the four seasons, he only wears a tattered garment and a straw rain cape. One meal can consume liters of rice, or one may not eat for months. Those who can predict good fortune and misfortune are regarded as gods by people. A lifetime of wandering, with no end in sight. He once died and came back to life at Jintai Temple in Baoji. His Taoist disciples called him "The Wandering of the Yang God". He visited the Wudang Mountains many times, built thatched cottages to live in, practiced alchemy, and predicted that the mountain would surely thrive in the future, instructs his disciples to "keep the incense well". Later, I entered Sichuan and explored the true beauty of Mount Qingcheng and Mount Heming. In the 17th year of the Hongwu reign of Emperor Taizu of the Ming Dynasty (1384), he composed the "Poem on the Rootless Tree of Dan", titled himself "Recorded by Zhang Sanfeng, a remnant of the Great Yuan Dynasty, in the thatched Cottage on Tianzhu Peak of Wudang Mountain". In the 24th year of the Hongwu reign (1391), Zhu Yuanzhang sent envoys to search for him in all directions, but there was no trace of him. During the Yongle period of Emperor Chengzu of the Ming Dynasty (1403-1424), a major renovation was carried out on Wudang Mountain, and a "Yuzhen Palace" was specially built for Zhang Sanfeng. He sent envoys several times to search for it but never found it. In the third year of the reign of Emperor Yingzong of the Ming Dynasty (1459), he was conferred the title of "Tongwei Xianhua Zhenren". Zhang Sanfeng believed that since ancient times, Taoist teachings have been passed down and are divided into two religions: the good and the evil. Confucianism, Taoism and Buddhism are all orthodox religions. Although they have different founders, "cultivating oneself and benefiting others leads to unity." Therefore, "Muni, Confucius and Laozi all called themselves the Tao." In his "Treatise on the Great Way", he said, "Confucianism is about following the way and adapting to The Times; Buddhism is about understanding the way and enlightening others; immortals are about hiding the way and saving others." He advocated that those who practice the Tao are cultivating the way of "Yin, Yang, nature and life", and "the sages of the three teachings all establish their teachings based on this way." He also believed that "metaphysics takes merit and virtue as its essence and golden elixirs as its application, and only then can one become an immortal." This is the outstanding aspect of Zhang Sanfeng's inner alchemy thought. He authored numerous works. Li Xiyue of the Qing Dynasty compiled "The Complete Works of Mr. Zhang Sanfeng", which was included in "The Essentials of the Taoist Canon".